bosu
n.— «Another innovation, this time from the United States, is Bosu—an acronym for “both sides up.” This is a giant inflatable exercise ball that is cut in half and which has replaced Step as the most sought after class type in American gyms.» —“Fitness meets fun in Italy” in Italy IOL (South Africa) May 27, 2005. (source: Double-Tongued Dictionary)
Further reading
Cat hair may be something you brush off, but cat hair is also a slang term that means “money.” In the same way, cat beer isn’t alcoholic — some people use cat beer as a joking term for “milk.” And imagine walking on a...
There are eight major planets, but more than a million minor ones, including asteroids. If you discover one, you get the honor of naming it. The Dictionary of Minor Planet Names includes minor planets named for rock bands, jazz musicians, poets, and...